<template>
  <header class="header">
    <h1>todos</h1>
    <input id="toggle-all" class="toggle-all" type="checkbox" v-model="selectAll">
    <label for="toggle-all"></label>
    <input
      class="new-todo"
      placeholder="输入任务名称-回车确认"
      autofocus
      v-model="taskName"
      @keydown.enter="addTask"
    >
  </header>
</template>

<script>
export default {
  data(){
    return{
      taskName:''
    }
  },
  props:['list'],
 methods:{
   addTask(){
     if(this.taskName.length==0){
       return alert('名称不能为空')
     }
     this.$emit('addTaskHanderl',this.taskName)
     this.taskName=''
   }
 },
 computed:{
   selectAll:{
     set(val){
       this.list.forEach(item => item.isDone=val
         
       );
     },
     get(){
       if(this.list.length==0){
         return false
       }
       return this.list.every(item=>item.isDone)
     }
   }
 }
}
</script>
